Savoia-Marchetti / SIAI SM.74 Millepiedi
Страна: Италия
Год: 1935


Flight, January 1935
A FAST ITALIAN MONOPLANE
Фотографии

Flight, January 1935

A FAST ITALIAN MONOPLANE
New Savoia Marchetti: Twenty-seven Passengers Carried at a Cruising Speed of 174 m.p.h.

  FLYING boats constructed by the Savoia Marchetti concern are well established in commercial operation, and their general features are known to readers of Flight. The company has, however, pursued of late a policy providing for the development of fast land machines of high- and low-wing monoplane types.
  Largest of the new Savoia series is the S.74 high-wing commercial monoplane, now under construction. In this machine, which uses a similar wing section to that employed on the S.55 flying boat and S.64 land plane which have established duration and distance records, the wing structure is of wood, and comprises three main spars, the whole wing being covered with plywood. Protective varnish is applied to the interior and the whole wing is given a covering of fabric. Four engine nacelles are carried below the wing, the inner pair being reinforced to support the compression legs of the undercarriage.
  Welded steel tubular construction is employed for the fuselage, in the nose of which is the pilots' cockpit fitted with dual controls. The passenger cabin is 7ft. 6in. wide and 6ft. 6in. high, and may be fitted with two alternative seating arrangements, one for twenty armchairs, with adjustable seats and backs, and the other for twenty-seven ordinary aircraft chairs. Large sliding windows on each side of the cabin serve as emergency exits. A bar and a lavatory are provided. Beneath the passenger cabin is a large luggage compartment with room for mail and freight.
  A split-type undercarriage is employed, the wheels being fitted with differentially controlled hydraulic brakes connected to the rudder bar, and enclosed in streamline fairings. The tail wheel is of the swivelling type. Welded steel tubes form the members of the empennage, and this is fabric covered. Tail plane incidence is adjustable in flight and the fin may be adjusted on the ground. Four 700 h.p. Piaggio "Stella IX" engines, driving three-bladed Savoia Marchetti metal variable pitch airscrews, are mounted on welded steel tube-bearers fixed to the lower surface of the wing. The fuel tanks, which form fairings behind the engines, may be dropped during flight. An air compressor is installed in the pilots' cockpit for starting the engines.

SAVOIA MARCHETTI S.74.
FOUR 700 H.P. PIAGGIO "STELLA IX's"

DIMENSIONS
  Span 89ft. 5in. (30 m)
  Length 64ft. (79,5 m)
  Height 18ft. (5,5 m)
  Wing Area 1,201 sq. ft. (120 m2)

WEIGHTS AND LOADINGS
  Weight empty 17,200 lb. (7 800 kg)
  Normal disposable load 11,907 lb. (5 400 kg)
  Maximum permissible disposable load 13,671 lb. (6 200 kg)
  Normal gross weight 29,106 lb. (13 200 kg)
  Maximum permissible gross weight 30,870 lb. (14 000 kg)
  Wing loading 22.55 lb. /sq. ft. (110 kg/m2)
  Power loading 10.41 lb./h.p. (4,64 kg/hp)

PERFORMANCE ON FOUR ENGINES
  Maximum speed at 3,280ft. (1000 m) at 2,330 r.p.m. 199 m.p. h. (320 km/h)
  Cruising speed at 3,280ft. (1000 m) at 2,050 r.p.m 174 m. p. h. {280 km/h)
  Climb to 3,280ft. (1 000 m) 3 min. 30 sec.
  Climb to 6,560ft. (2 000 m) 7 min. 30 sec.
  Climb to 9,840ft. (3 000 m) 12 min. 20 sec.
  Climb to 13,120ft. (4 000 m) 19 min.
  Climb to 16,400ft. (5 000 m) 30 min.
  Service ceiling 19,680ft. (6 000 m)

PERFORMANCE ON THREE ENGINES
  Service ceiling 9,840ft. (3 000 m)
  Maximum speed 162 m. p. h. (200 km/h)

PERFORMANCE ON TWO ENGINES
  Service ceiling 3,280ft. (1000 m)
  Maximum speed 124 m.p.h. (200 km/h)
View of the first S. 74, I-URBE. The ground shot clearly shows the original paint scheme and aileron horn balances.
THE LARGEST SAVOIA: The Savoia-Marchetti S.74 carries twenty-seven passengers at a cruising speed of 174 m.p.h. This cantilever monoplane, which is distinctly reminiscent of the Fokker F.36, was described in Flight on January 3. It may be used on part of the Sabena-Ala Littoria service between London and Rome and it is proposed that the passengers should be fed with oxygen while crossing the Alps.
The first Savoia Marchetti S.74, I-URBE. It is painted in modified Ala Littoria livery, with the Italian flag on the fin. I-URBE first flew on November 16, 1934; following service with Ala Littoria it was requisitioned for military use on Italy’s entry into World War Two, and was destroyed during an Allied bombing raid on November 2, 1941.
A Savoia S.74 of Ala Littoria.
A Savoia-Marchetti S74 (four Piaggio "Stella" 700 h.p. motors) of Ala Littorio Airport, Rome.
The Pegasus-engined S.74 I-ROMA, with most of its underfloor baggage hold doors open.
The view of the S.74 clearly shows the engine installation and the cabin and cockpit windows. The Italian and Ala Littoria flags were being flown when the photograph was taken.
The first S.74, I-URBE, in service with Ala Littoria.
View of the first S. 74, I-URBE. It is seen on a test flight in the winter of 1934-35.
A view of the 24-seat cabin of an Ala Littoria S.74, looking aft.
A sectional view of an S.74's fuselage, showing the underfloor luggage hold.